Cleaner



United States Patent M 3,218,260 CLEANER Thaddeus Lewandowski,Burlington, Iowa, assignor, by

mesne assignments, to Bonewitz Chemicals, Inc., Burlington, Iowa, acorporation of Iowa No Drawing. Filed June 15, 1960, Ser. No. 36,117 1Claim. (Cl. 252142) This invention relates to an improved generalcleaner. It is particularly useful for washing milk cans and containersof glass, plastics, and metals and for cleaning conventional equipmentin the dairy, packing house and food processing industries. Theinvention is also useful in the treatment of water to provide a suitablerinse, for example, and in fact finds utility wherever hard water andsoil conditions are present. The invention further finds utility in suchindustrial operations as water hardness control in enclosed systems.

We have found that an aqueous composition containing an organic acid oran inorganic acid or mixtures of the same, e.g., gluconic acid, glycolicacid, phosphoric acid and mixtures of the same with an anionic syntheticdetergent as described in the patents of Parker-Bonewitz, Nos.2,338,688, 2,338,689 and 2,424,049, are substantially improved fortreating hard water and for enhancing their cleaning power whenreinforced with certain nonionic synthetic detergents having the usualhydrophilic and hydrophobic components or bases.

These agents according to our discovery must contain at least aboutmoles of ethylene oxide per mole of the hydrophobic base, with theethylene oxide constituting at least about 70% of the nonionic syntheticdetergent. When synthetic detergents of this character are introducedinto a composition of the acid and the anionic synthetic detergent, thesolubility of the mixture in hard water is substantially improved. Inthis manner we are able to obtain and retain clarity in water of about30 to 100 or more grains per gallon hardness at temperatures up to about212 F. or boiling. It is interesting to observe that the improvedresults take place regardless of the acid or anionic syntheticdetergents which are present in the mixture.

The results achieved by this invention were unexpected and areconsidered remarkable because when the nonionic synthetic detergentshaving characteristics below the critical properties above recited wereadded to a mixture of the acid and anionic synthetic detergent, thereduction of turbidity was not appreciable. However, we discovered byusing the nonionic synthetic detergents having at least about 10 molesof ethylene oxide per mole of hydrophobic base and containing at leastabout 70% ethylene oxide (which are compounds outside of the popularconception and use of nonionic synthetic detergents) that the improvedresults are obtained in compositions containing the acid and the anionicsynthetic detergents.

Of particular significance, it was observed that the presence of thehigher molecular weight nonionic synthetic detergents improved thesolubility of the well known acid and anionic synthetic detergentmixtures so that even in the case of extremely hard water of upwards of100 grains or more per gallon, clarity was assured, showing conclusivelythat the invention resulted in maintaining hard Water salts and othermaterials present in the water permanently in solution, and at extremelyhigh temperatures up to and including boiling.

The practical value of our discovery can best be appreciated when it isrealized that milk cans, and food containers, as well as dairy, foodprocessing and similar equipment, must be maintained both physically andbiologically clean. The present invention assures that at substantiallyall temperatures including high temperatures,

3,218,260 Patented Nov. 16, 1965 soils and wastes will not only beremoved from the equipment but will be permanently prevented fromsettling out or redepositing whereby scaling and objectionableaccumulation of soils will be held to a minimum or is substantiallyeliminated. The unexpected achievement of this invention becomes morepronounced when it is appreciated that water hardness progressivelyincreases with the increase of the soil load in the aqueous solution. Itis to overcome the efifect of such condition that this improvement isnecessary in present day operations in the food processing and dairyindustries and for cleaning in genera].

The advantages of the present invention will be more completelyunderstood upon reference to the following table which illustrates bycomparison the percent of milk cans showing milkstone in a top qualityconventional can washer during the use of at least one of the bestcleaning compounds and the present invention.

TABLE 1 Percent Cans Showing Milkstone Month 1957 1958 1959 Machine HandHand Washed Washed Washed* January 30. 2 5. 6 8. 3 24. 2 8. 6 4. 9 25. 89. 6 7. 5 19. 7 4. 9 6. 1

Hand Washed* May 9. 3 6. 2 2. 8 Periodically Present Invention June 5. 42. 1 5. 1 July--- 6.7 1.9 4.5 4. 9 Periodically 3. 3 8. 1 3. 4 3. 3Oct0ber 8. 7 5. 9 3. 2 Periodically November 4. 7 5. 8 5. 5 December 5.5 8. 6 2. 6

*Hand washed periodically in addition to being machine washed.

The following examples illustrate the manner in which the compositionsare produced, all amounts being recited by weight of active materials.

Example 1 9% of gluconic acid, 5.1% of alkyl aryl sulfonate (Ultrawet D8of Atlantic Refining Co.), 4% nonionic synthetic detergent (Igepal CO880, Antara Chemical Co.) and water to make 100% are suitably mixed atroom temperature. The composition is then ready to be employed as acleaner upon suitable dilution in water. Some of the composition Wateris supplied by the gluconic acid which is preferably introduced as a 50%solution but may be introduced in solution of any amount notably 25 toconcentration. The composition has a pH on the acid side below pH 2.

Example 2 This example is like Example 1, except that instead ofgluconic acid, 13 /2 of phosphoric acid is used.

Example 3 This example is like Example 1, except that it contains 9%gluconic acid and 13 /2 phosphoric acid.

Example 4 This example is like Example 1, except that it contains 9%gluconic acid and 12.6% glycolic acid.

Example 5 This example is like Example 1, except that 13 /2% phosphoricacid and 12.6% glycolic acid were used.

Example 6 ticular criticality. For instance, the phosphoric acid ofExample 2 is useful in amount up to about 65% and compositionscontaining as much as 50% of gluconic acid have been found feasible.

The concentrated or stock solutions of which the foregoing examples arerepresentative as stated will have a pH on the acid side, i.e., below 2.In some cases the pH may be below 1.0.

The lower limit of active anionic detergent is about 1.0% and the upperlimit is not particularly critical. Up to 10% has been foundsatisfactory but greater amounts are not precluded and have also beenfound useful.

While the lower limit for the nonionic detergent is about 0.4% and theupper limit likewise is not critical, up to 10% having been found usefuland larger amounts also having been successfully employed, all amountsbeing by weight of active ingredient. The amounts used of the respectivesynthetic detergents is dependent on the character of the water, thesoil conditions encountered and other properties connected with thecleaning operation, the lower limits recited being somewhat critical inamount to assure a successful result but the upper limits not beingcritical as recited since an excess will not preclude a successfulresult.

In using the concentrates they are diluted with water and usually byemploying 1 oz. of the concentrate per gallon of water. This dilution ofcourse will be carried out by the operator and varied in accordance withthe character of the water used, the soil conditions, and the generalnature of the metal, glass or plastic surface to be cleaned and ofcourse the method of application. The diluted solution is useful withcleaning systems which employ circulation, spraying, soaking, brushingby hand and in fact in all of the usual ways as practiced by theparticular industry. In some cases, of course, the dilution is alsovaried in accordance with the particular type of equipment being cleanedand by the cleaning procedures in use at a particular plant. In thisconnection, the product may also be used as a final rinse. As apractical matter, as little as about ounce of the concentrate per gallonof water or less has been found useful and under certain conditions itmay be found imperative to use the concentrate at full strength.

The acids which are useful in this invention in accordance with theforegoing examples are phosphoric, glycolic and gluconic and mixtures ofthe same, namely, glycolic and gluconic, phosphoric and gluconic andphosphoric plus glycolic. The relative proportions in which the mixturesare made up is not critical. Thus, in Example 3, the amount of gluconicacid could be greater than the amount of phosphoric acid and in Example4 the gluconic acid can be in greater amount than the glycolic, while inExample 5 the amount of phosphoric can be greater than the amount ofglycolic. The total amount of the acids present should be within theranges set forth above. The foregoing are preferable but other acidswhich may be used in the same manner are citric, lactic, levulinic,tartaric, oxalic, fumaric and aconitic. Inorganic acids which may beused alone or mixed with each other or with the organic acids aresulfamic, hydrochloric, sulphuric, mixed acids, alkali metal acidphosphates including sodium acid pyrophosphate, monosodium phosphate,sodium bisulfate, and the sodium and potassium acid phosphates ingeneral.

The nonionic synthetic detergents which are useful, may be statedgenerically to be nonyl and t-octyl, phenols or, polyoxypropylene havingan average ethylene oxide content of at least about 70% and an averagenumber of moles of ethylene oxide per mole of hydrophobic base of atleast about 10. The useful nonyl phenols are the Igepals made by AntaraChemical Co. and sold under the trade names of Igepal CO-7l0, IgepalCO-730, Igepal CO-850 and Igepal CO-880. Thus, t-octyl phenols made byRohm and Haas and sold under the trade names of Triton X102, TritonX-165, Triton X- 205, and Triton X-305. A suitable and preferablepolyoxypropylene is made and sold by Wyandotte Chemical Co. under thetrade name of Pluronic F-68.

There are many other types of nonionic synthetic detergents or wettingagents which are suitable and the foregoing are indicated asrepresentative in that they have the pronounced effect when added to anacid and and anionic synthetic detergent in accordance with theforegoing examples of affording enhanced cleaning action on the one handand imparting the permanent clarity to the cleaning solutionnotwithstanding that the condition of the water be as high and evengreater than 100 grams per gallon of hardness and the temperatures rangefrom room temperature to and through boiling 212 F., on the other'hand.

With respect to the anionic synthetic detergents employed, with thisinvention, and illustrated in the foregoing examples, a great many maybe utilized and they are generally of the class consisting of alkyl arylsodium sulfonates in which the alkyl may be decyl or dodecyl and thearyl may be benzene or naphthalene. T'hus suitable examples are UltrawetDS made by Atlantic Refining Co. and containing at least decyl benzenesodium sulfonate, Nacconol Z made by National Aniline Co. and containingat least 85% dodecyl benzene sodium sulfonate, and Petro AA made byPetro Chemical Co. and containing at least 98% alkyl naphthalene sodiumsulfonate.

In a mixture of gluconic and glycolic acids which proved quitesuccessful we used 6% of the Ultrawet DS, with 4% of the Igepal CO710 orIgepal CO730; as described in the foregoing examples. Also we used 6% ofthe Nacconol Z with 4% of the Igepal (IO-730 or Igepal CO-85O in themixture of gluconic acid and glycolic acids in accordance with theforegoing examples. We further successfully used 5.2% Petro AA inconnection with 6% of the mixture of gluconic and glycolic acids, withIgepal CO73O as in the foregoing examples.

In the appended claims wherein I have called for a cleaning compositioncomprising an acid selected from the group consisting of organic andinorganic acids and an anionic synthetic detergent, the improvement isrecited as comprising in such a composition a nonionic syntheticdetergent having at least about 70% ethylene oxide and about 10 mols ofethylene oxide per mol of the hydrophobic base of said nonionicdetergent, and water. Also, the claims bring out that the pH is on theacid side, i.e., is less than about pH 2 and may be less than aboutpH 1. The organic and inorganic acids are well known cleaning agents asare the anionic detergents, but in reciting the nonionic syntheticdetergents, I have for purposes of definiteness stated them to have theformulae:

in which R is nonyl phenyl, and n is at least about 10 and equivalent toat least about 70% of the finished product.

(B) R(CH CH O) OI-I in which R is t-octyl phenol and n is at least about10 and equivalent to at least about 70% of the finished product.

in which R is polyoxypropylene and a plus b representing mols ofethylene oxide is equivalent to at least about 70% of the molecule.

I claim:

An acid cleaning composition consisting essentially of at least about 9%gluconic acid, at least about 1% of a higher alkyl aryl sulfonate, atleast about 0.4% of a nonionic synthetic detergent selected from a groupconsisting of ethylene oxide condensates of nonyl phenols, t-octylphenols and polyoxpropylene, said detergent having at least about 10mols of ethylene oxide per mol of the hydrophobic base of said non-ionicdetergent and water to make 100%, said cleaning composition having a pHbelow about 2, said composition increasing the solubility of thedetergents in had water and obtaining and retaining clarity in water asmuch as to grains per gallon hardness up to boiling temperature.

References Cited by the Examiner UNITED STATES PATENTS 2,338,689 1/1944Parker et a1 99182 2,424,049 7/ 1947 Parker et al. 1343 2,585,127 2/1952Holman et a1 252136 2,629,696 2/ 1953' Dodd et a1 2512136 2,878,1883/1959 Callahan 252136 2,901,434 8/1959 Butcosk 252136 2,977,315 3/1961Scheib et al 252106 3,029,193 4/1962 Winicove et al. 252-106 XR JULIUSGREENWALD. Primary Examiner.

